Merge values in array from multidimensional array-CodePudding

I'm a JS beginner and I'm stuck with array/objects items. I get a JSON file with a fetch request and I would like to extract a part of the data.

My data looks like this:

{
"profil": [
 {
  "name": "",
  "id": ,
  "city": "",
  "country": "",
  "tags": ["", "", "", ""],
  "text": "",
  "price":
 },

So it's an object, which contain an array which contain a bunch of objects which contain a "tags" array....

I don't find a way to access tags items (without array index) with forEach loops... My final purpose with this is to collect a single list of tags that exists in my object list.

How can I do this?

CodePudding user response：

Using Array#flatMap:

const data = {
  "profil": [
    { "tags": ["1", "2", "3", "4"] },
    { "tags": ["5", "6", "7", "8"] }
  ]
};

const tags = data.profil.flatMap(({ tags = [] }) => tags);

console.log(tags);

Edit: if you need the tags to be unique, you can use Set:

console.log([...new Set(tags)]);